APA (7th ed.) Citation

Froyen, R. T., & Greer, D. F. (1989). Principles of economics. Macmillan.

Chicago Style (17th ed.) Citation

Froyen, Richard T., and Douglas F. Greer. Principles of Economics. New York: Macmillan, 1989.

MLA (9th ed.) Citation

Froyen, Richard T., and Douglas F. Greer. Principles of Economics. Macmillan, 1989.